Department of Plant Production & Protection, Faculty of Agriculture & Veterinary Medicine, An-Najah National University, Nablus, West Bank, Palestine.
J Appl Microbiol. 2020 Aug;129(2):400-410. doi: 10.1111/jam.14613. Epub 2020 Feb 28.
To isolate and characterize a native strain of Trichothecium roseum infecting the immatures of Pauropsylla buxtoni on fig leaves, to study the morphological features of the isolated strain, then to test the entomopathogenic effect of the isolated strain against the immatures of P. buxtoni on fig leaves.
The isolated strain of T. roseum produced pink mycelial growth on culture medium with septate mycelium and conidiophores. It also produced two-celled conidia with elliptical to pyriform shape born at the tip of conidiophores. Molecular characterization of the isolated strain confirmed the identity of the strain as T. roseum. In bioassays, application of conidial suspension of the isolated strain against the 4th instar of P. buxtoni immatures infesting fig leaves showed an obvious entomopathogenic effect of the applied fungus strain against the targeted insect. This effect was exhibited by the death of treated P. buxtoni immatures with the fungus. The dead insects were characterized by the presence of pinkish mycelial growth on the outer surface which is characteristic to the fungus, in addition to the positive isolation of the fungus from internal tissues of treated insects after a proper external disinfection. Moreover, significant differences (at P < 0·018) were obtained between the means of mortality % of P. buxtoni immatures treated with different concentrations of conidial suspension of the fungus.
The overall results confirm the entomopathogenic effect of T. roseum against P. buxtoni immatures infesting fig leaves. Significant mortalities of P. buxtoni immatures were obtained when the different concentrations of the fungus conidial suspension were bio-assessed against the insect.
The tested strain of T. roseum can be applied as biocontrol agent of P. buxtoni on fig leaves within an integrated control programme to reduce the impact of pest on fig trees.
从感染榕小蜂若虫的榕树叶上分离并鉴定一株天然的玫瑰炭疽菌，研究分离株的形态特征，然后测试分离株对榕树叶上榕小蜂若虫的致病效果。
分离出的玫瑰炭疽菌在含有隔膜菌丝和分生孢子梗的培养基上产生粉红色的菌丝生长，还产生了两端细胞的分生孢子，呈椭圆形至梨形，生于分生孢子梗的顶端。对分离株的分子特征进行鉴定，证实该菌株为玫瑰炭疽菌。在生物测定中，应用分离株的分生孢子悬浮液处理感染榕树叶的榕小蜂第 4 龄幼虫，显示出该真菌菌株对目标昆虫具有明显的致病效果。这种效果表现为用真菌处理过的榕小蜂死亡。死亡的昆虫具有粉红色的菌丝生长在外部表面的特征，这是真菌的特征，此外，在适当的外部消毒后，从处理过的昆虫内部组织中可以分离出真菌。此外，用不同浓度的真菌分生孢子悬浮液处理榕小蜂若虫后，死亡率的平均值之间存在显著差异（P<0·018）。
总的来说，玫瑰炭疽菌对感染榕树叶的榕小蜂若虫具有致病效果。当用不同浓度的真菌分生孢子悬浮液对昆虫进行生物测定时，获得了显著的榕小蜂若虫死亡率。
测试的玫瑰炭疽菌菌株可以作为榕树上榕小蜂的生物防治剂，纳入综合防治计划，以减少害虫对榕属树木的影响。
